


wild thing (i think i love you)

by cinnabun



Category: Undertale (Video Game)
Genre: Alternate Universe - Underswap, F/M, Porn, Porn With Plot, Porn with Feelings, commission
Language: English
Status: Completed
Published: 2018-05-10
Updated: 2018-05-10
Packaged: 2019-05-05 00:02:44
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 2,498
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/14604672
Author URL: https://archiveofourown.org/users/cinnabun/pseuds/cinnabun
Summary: TFW the After-Party is so much better than the Original Party.{ 2.5k One-Shot Commission: Underswap!Napstablook/Reader NSFW }





	wild thing (i think i love you)

❤ ❤ ❤

You drove him wild.

Everything you did. The way you spoke, the way you laughed, the way your eyes sparkled under the club lights. The way those same lights trailed down your body, catching every curve as you danced. Napstaton took another swig of his drink, the taste of sour apple fresh on his tongue as he watched your hips sway to the beat. He licked his lips.

It wasn’t often that you got nights like this all to yourselves. And granted, going out to a club wasn’t exactly a “private” situation, but it gave you a chance to let loose for a while. He enjoyed getting to see your moves up close, instead of trying to pick you out from a crowd of hundreds of faces from his DJ Booth. The music thrummed, so deep and loud that it was making his entire body rumble. Maybe it was just the drink settling in, but everything felt so much warmer than he’d remembered it being. Despite the frantic whirring of his internal fans, the more he watched you, the hotter it felt.

As the long wound down, you stumbled over to him, clutching your shoes in one hand and brushing your hair from your face. A few strands remained, plastered by the sweat on your brow. Yet your makeup stayed in place perfectly. Napsta laughed to himself, knowing that the “waterproof label” wouldn’t be worth a damn in a minute.

You said something, but he couldn’t hear you. All he could do was stare at your lips as they moved. They looked so soft in this light. The color of your lipstick made him think of candy. He wondered if you tasted as sweet as you looked—

“—Napsta! Napsta!” He blinked furiously. Your worried expression slowly came into view as you waved a hand in front of his eyes for a moment. When he gave you a lopsided grin, you sighed. “I think we should turn in for the night. My feet are killing me and I’m not up for any more drinks.”

“Aw,” he mumbled, disregarding your squeaks of surprise as he dragged you into his lap. Gently, Napsta pillowed his face against your chest, the sound of your heartbeat like thunder against his audio receptors. It was the most beautiful thunder he’d ever heard. “But we were havin’ such a good time! Well, I was, anyway.”

Rolling your eyes, you unpeeled yourself from his embrace, ignoring the high-pitched, puppylike whine he let out. “Then that means we should definitely head back.”

“But, baby!” Napsta moaned, flopping his head back dramatically, “I don’t wanna go yet! The party’s just gettin’ started!”

He wasn’t going to budge at this rate. You had to change tactics.

“Okay. Buuut,” you began slowly, gripping his chin to tilt it in your direction. You watched his blurry optics trail the path your finger traced down his chassis. “What if we had an after-party? A _private_ after party.”

The lights of his pupils spun drunkenly, shifting into stars like a dial had been turned inside him. Napsta was on his feet in moments, yelling for the check. You tried not to laugh, watching as he flailed his noodle-y limbs like your lives depended on it. In his buzzed state-of-mind, the pipes of his arms flopped about loosely. He looked like one of those balloon people you usually saw outside of car lots.

He was too cute for his own good, sometimes.

His charm wore off when he tried to slide his hand up your skirt in the back of a taxi.

“Napsta!” You hissed, pushing him back. “We’re in a cab!”

He just kept kissing your neck, nuzzling comfortably against the dip. “Sorry, baby. Just can’t help myself.”

“You’ll have to till we get back home, so. Behave! If you don’t, there’ll be no party at all.” You didn’t like to snap at him, especially during his affectionate moments, but if the cab driver caught onto what he was doing, you’d die of embarrassment. Obediently your botfriend retreated, crossing his arms over his chest. You smiled at the grumpy little pout he wore. God, he was just so cute.

Your phone screen blared to life hundreds of notifications. Just one of the perks of dating a celebrity—you get honorary celeb-dom. It was stressing sometimes, but mostly, you adored your “fans.” They all seemed like such sweet (if not eccentric) people. Smiling, you propped the camera up, leaning against the bot’s shoulder with a peace sign lifted. The picture snapped just as before he turned his head, giving you a perfect view of his grouchy simper peeking from over the photo you’s shoulder.

“ _Look who I caught pouting! XP_ ,” You wrote underneath. The Undernet’s reaction was instantaneous. The photo was blasted with likes and re-peeks. More than a handful of people left comments along with their shares, mostly along the lines of “ _Aw!_ ” and “ _#2precious4thisworld_.”

“Baaaabe,” Napsta whined again, “You’re making me look uncool in front of my lovelies!”

“Oh, you know you love it.” The smile curling at the edge of his lips was so obvious. “I bet by tomorrow, you’ll be cooing about it on your VidU.”

He was quiet for a moment, before the serious expression broke. He beamed, looping an arm around your shoulders. “Well, yeah! I look super-hot when I’m pouting. It’s like a smolder!”

“A smolder?” You crooked a brow. “And when have you ever done that?”

“Lotsa times! You’ll know it when you see it.” Napstaton waggled his brows. “I’ll give you a private showing at the after-party.”

Both of you burst into wild giggles, just loud enough to catch the driver’s attention. He met your gaze momentarily, and you ducked back, stifling your laughter. The heat burning across your face trailed the length of your spine, filling each of your nerves as it worked down to your core. One thing was for sure: you were going to have a hell of a time at this “after-party.”

❤ ❤ ❤

Napsta seemed to share the same sentiment, because the moment you stumbled out of the cab his hands wouldn’t leave you. You had to drag him to the elevator, ignoring the looks of jealousy and amusement your fellow Resort goers were giving you. It was just your luck that there were a few people still in the elevator when it arrived, or else you were certain the overly-excited bot would have attempted to push his luck with getting you both caught.

It felt like there was a timer counting down, though you knew if anything came up, you could easily put the mood on hold until it was taken care of. Still, it was kind of thrilling, picturing your boyfriend getting so fed up with waiting that he pinned you to the resort wall and—

You fumbled in front of your door for the keys. It was hard to keep your focus with Napsta kissing your neck, but you managed to get it unlocked just as his hands wandered down to the hem of your dress.

He wasted no time then, whirling you around and dragging you into a passionate kiss. His foot kicked out, slamming the door so hard that it made the walls shake. You flinched a little, but melted into the kiss quickly, practically purring as his fingers threaded through your hair.

The robot pressed into you, gently guiding you backwards. You bumped into the wall, the excitement of your previous fantasy coming full-blast to the front of your mind. His hands fumbled like that of an awkward teenager during his first make-out session, squeezing at every handful of naked skin that he could get to.

Heat was everywhere, like you were standing next to a furnace. It radiated from the tiny capsule in his waist, where his SOUL bounced and fizzed impatiently. Smiling, you pulled back and gently pressed a hand to his chest to keep him at bay.

He whined again, “ _Baaabe_ —”

Holding a finger to his lips, you shushed him. Grumpily, he slouched, simpering as you led him into the bedroom with a giggle. As much as you would have liked to bring your fantasy to reality, your feet were still killing you. At the very least, you wanted to lie down.

You didn’t have long to wait. Quick as a flash, you were in the air, wiggling in Napsta’s arms for a split-second before he tossed you onto the mattress. While you laid there, laughing, he took his chance. Within moments he was hovering over you, hands gripping your wrists as he pressed you into the bed with a deep, lingering kiss.

“Finally,” Napsta groaned, burying his face in the dip of your neck. A warm flush rolled through you as his fangs brushed your shoulder teasingly. “God, you don’t know how long I wanted to do this. I’ve been waiting all night.”

Something about the way he said it made you shiver. He sounded so sincere. You’d never expected to have that kind of effect on anybody, much less someone like him. He was so bright, so…incredible.

But right now, he was looking at you like were the only star in his eyes.

“I love you,” he said, in a soft voice that you’d only heard a handful of times before.

You fought back the tears threatening to build. “I love you too.”

“Nngh.” Napsta flopped into your chest, the groans mumbled against your skin. “I love you so much.”

A giggle bubbled in your chest as you hugged his head, gently stroking your nails over his synthetic scalp. “I love you more.”

“Nuh-uh!” He sounded insulted that you would even insinuate such a thing, a playful challenge in his tone. “I’ll prove it, babe. This is gonna be the raddest night of your life.”

“It already is.”

A moment of silence passed then, as you did nothing more than stare at one another. It wasn’t a contest, or even a conversation. You just enjoyed the sight of one another, basking in the shared warmth of your bodies pressed together.

Slowly, Napstaton leaned onto his haunches. You watched in confusion as he wriggled back down the length of the bed. “What are you up to?”

His answer was to push the hem of your dress up until it bunched around your hips. Though curious, you accommodated his actions, lifting your body to allow him to hook your legs into a more comfortable position. It finally clicked when his eyes raked downwards, locking onto the junction of your hips. Testing your theory, you swayed them back and forth, watching his gaze chase the curve of your little pink undies.

“Ohh, I see.” He flashed his fangs when you widened your legs even further, hooking a finger under the elastic band of your undies teasingly. “Go ahead then, superstar. Make my night.”

Next thing you knew, your hands were clasped over your mouth, trying desperately to hold back the rising urge to scream. The challenge had been duly accepted, and now all you could do was lie back and moan as he showed you the best damn time of your life.

Truth be told, this was kind of cheating in your book. Out of the two of you, only one of you was equipped with vibrating features. And he was putting every single one of them to good use. His fingertips teased your opening playfully, while he treated your clit like a piece of candy, licking and sucking in a way that had your legs shaking and hips bucking.

The swirl of his hand dipped inwards. Two of his fingers pushed deep into you, causing your hips to clamp down almost immediately. You hadn’t come quite yet, but goddamn were you getting close. Pleasure shot through your nerves in uneven waves, like tingling streaks of lightning coursing from your core into every corner of your body. When his tongue curled around the bundle of nerves beneath your hood, you gave into the desperation, and let your eyes roll back with a deep, needy moan.

Your entire body felt heavy with the need to find release. The sounds Napstaton was making weren’t helping either. Between the most lewd slurping noises you’d heard outside of pornos, he was groaning in a way that made your entire body tremble. Just as you felt that searing heat of an oncoming orgasm beginning to wind it’s way into your core, he pulled back.

You whined against the absence of pressure, wiggling fruitlessly in an attempt to chase his retreating mouth. Thankfully, he didn’t seem in the mood to tease you too much, as the thickness of his fingers was quickly replaced with the rock-hard sensation of his cock grinding against your entrance. It was the same baby blue as the rest of his ensemble, with streaks of gold crossing the silicone material like some sort of ornate tattoo. Every so often, the light would catch it just right, and you swore the pattern moved, shifting like an endless galaxy.

Was it weird to say that he had a beautiful dick? Maybe. But you really wanted said dick in you, ASAP.

The smirk on Napstaton’s face was lecherous as he grinned down at you, licking the remnants of your juices from his chin. Gently, he leaned down, meeting your lips at the same time that his hips pushed forward. You jerked at the feeling of him sliding into your heat, shivering until the base pressed between your legs. He was buried so deep, and you could feel every inch of him.

Then, almost cruelly, he dragged you even closer, and began a steady, soft pace that had you whining and pleading.

“Faster,” you begged. “Harder. Please, Napstaaa…”

With the warble of your voice, the pace shifted. His eyes gleamed gold in the dim light, the only thing you could make out past the waves crashing through your hips. Your mind buzzed in all different directions, but only one thing remained clear: you were coming.

_Oh god, you were coming, you were gonna, oh fuck—!!_

He held you through the aftershock, still buried to the hilt as you dragged his orgasm from him. Your moans reflected in the silence, your shaky, broken cry a wonderful accompaniment to his soft, awe-struck whimper. Even as the fire faded, and the pressure of the coil that had been in your womb began to unwind, you clutched onto each other.

Your hips trembled as he slowly pulled out, watching the luminescent by-product of your love-making seep from between your legs and onto the sheets. Still trying to regain his composure, Napsta leaned forward, pressing his forehead to yours. “How was that? I totally rocked your world, right?”

You just giggled, pulling the blanket over his head. He let out a surprised squawk, caught off-guard for a moment before he returned the favor, the two of you rolling around like a pair of lovestruck teenagers.

This was the best after-party you’d ever been to.

❤ ❤ ❤

**Author's Note:**

> Here it is, folks: A 2.5k NSFW Underswap!Napstablook/Reader fic I was Commissioned by a lovely returning customer, who I will keep Anonymous for privacy's sake! Thank you again for Commissioning me, darling, I greatly appreciate it! (Also that title is 100% based on another wonderful fic I love with the same moniker aheh.)
> 
> I'm still working on the next Chapter of S.O.P. and the next installment of "snm" so keep your eyes peeled for those Coming Soon! If you have any questions, requests, or recommendations, you can send them to me on tumblr "@butttspie" ! Thanks for reading!
> 
> Comments are always appreciated !!


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